What Is Seasonal Affective Disorder (SAD)?

Roxanne Dryden-Edwards, MD

Dr. Roxanne Dryden-Edwards is an adult, child, and adolescent psychiatrist. She is a former Chair of the Committee on Developmental Disabilities for the American Psychiatric Association, Assistant Professor of Psychiatry at Johns Hopkins Hospital in Baltimore, Maryland, and Medical Director of the National Center for Children and Families in Bethesda, Maryland.

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

What is seasonal affective disorder?

Seasonal affective disorder (SAD) is a type of depression that tends to occur (and recur) as the days grow shorter in the fall and winter. It is believed that affected people react adversely to the decreasing amounts of sunlight and the colder temperatures as the fall and winter progress. It is important to note that although seasonal affective disorder usually presents in the fall and winter there are those who suffer from this condition during the summer instead of, or in addition to, during the fall or winter.

Seasonal affective disorder has not been long recognized as an official diagnosis. The term first appeared in print in 1985. Seasonal affective disorder is also sometimes called winter depression, winter blues, or the hibernation reaction.

The incidence of seasonal affective disorder increases in people who are living farther away from the equator. Statistics on seasonal affective disorder in the United States include that this disorder occurs in
1% to 10% of adults, and its prevalance is dependent on geographical location. Seasonal affective disorder is less common where there is snow on the ground. Seasonal affective disorder is about four times more common in women than men, and the average age of people when they first develop this illness is 23 years of age. People of all ages can develop seasonal affective disorder.

What are the symptoms of seasonal affective disorder?

Although there is no specific diagnostic test for the illness, it is understood that symptoms of seasonal affective disorder include tiredness, fatigue, depression, crying spells, irritability, trouble concentrating, body aches, loss of sex drive, poor sleep, decreased activity level, and overeating, especially of carbohydrates, with associated weight gain. When the condition presents in the summer, the symptoms are more commonly insomnia, poor appetite, and weight loss, in addition to irritability, difficulty concentrating, and crying spells. In severe instances, seasonal affective disorder can be associated with thoughts of suicide.

The symptoms of seasonal affective disorder typically tend to begin in the fall each year, lasting until spring. The symptoms are more intense during the darkest months. Therefore, the more common months of symptoms will vary depending on how far away from the equator one lives.